Perfusion Imaging Distinguishes Exercise Pulmonary Arterial Hypertension at Rest.
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ABSTRACT:
SUBMITTER: Kohli P
PROVIDER: S-EPMC7401417 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Despite recent advances, the prognosis of pulmonary hypertension (PH) remains poor. While the initial insult in PH implicates the pulmonary vasculature, the functional state, exercise capacity, and survival of such patients are closely linked to right ventricular (RV) function. In the current study, we sought to investigate the effects of maximum incremental exercise on the matching of RV contractility and afterload (i.e. right ventricular-pulmonary arterial [RV-PA] coupling) in patients with exercise PH (ePH) and pulmonary arterial hypertension (PAH). End-systolic elastance (Ees), pulmonary arterial elastance (Ea), and RV-PA coupling (Ees/Ea) were determined using single-beat pressure-volume loop analysis in 40 patients that underwent maximum invasive cardiopulmonary exercise testing. Eleven patients had ePH, nine had PAH, and 20 were age-matched controls. During exercise, the impaired exertional contractile reserve in PAH was associated with blunted stroke volume index (SVI) augmentation and reduced peak oxygen consumption (peak VO2 %predicted). Compared to PAH, ePH demonstrated increased RV contractility in response to increasing RV afterload during exercise; however, this was insufficient and resulted in reduced peak RV-PA coupling. The dynamic RV-PA uncoupling in ePH was associated with similarly blunted SVI augmentation and peak VO2 as PAH. In conclusion, dynamic rest-to-peak exercise RV-PA uncoupling during maximum exercise blunts SV increase and reduces exercise capacity in exercise PH and PAH. In ePH, the insufficient increase in RV contractility to compensate for increasing RV afterload during maximum exercise leads to deterioration of RV-PA coupling. These data provide evidence that even in the early stages of PH, RV function is compromised.
| S-EPMC6643191 | biostudies-literature
Project description:Pulmonary hypertension (PH) is characterized by progressive dyspnea, fatigue, and reduced exercise capacity. Despite medical treatment, outcomes remain poor. While exercise training is well established in patients with heart failure, it is less established in patients with PH. This single-blind, randomized controlled pilot study examined the feasibility and effect of 12-week outpatient exercise (multidisciplinary rehabilitation or home walking program) on hemodynamics using cardiac magnetic resonance imaging (cMRI) and right heart catheterization (RHC) in patients with pulmonary arterial hypertension (PAH), a subset of PH. Sixteen participants were randomized to either multidisciplinary outpatient rehabilitation or a home walking program for 12 weeks. Primary outcome measures were changes in right ventricular ejection fraction and stroke volume index on cMRI. Secondary outcome measures included hemodynamics on RHC, quality of life (QOL), muscle strength (handgrip and vital capacity) and 6-min walk test. This preliminary, pilot study suggests that outpatient exercise interventions may be associated with improved hemodynamic function (mean pulmonary artery wedge pressure, stroke volume, and stroke volume index), QOL (PH symptoms, depression, and anxiety), and muscular strength (vital capacity and handgrip strength) for people with PAH, but was not adequately powered to make any formal conclusions. However, our outpatient programs were feasible, safe, and acceptable to participants. Future studies are required to further explore the potential hemodynamic benefits of exercise in PAH.
| S-EPMC9248794 | biostudies-literature
Project description:Here, we tested the hypothesis that severe pulmonary arterial hypertension impairs retrograde perfusion. To test this hypothesis, pulmonary arterial hypertension was induced in Fischer rats using a single injection of Sugen 5416 followed by 3 wk of exposure to 10% hypoxia and then 2 wk of normoxia. This Sugen 5416 and hypoxia regimen caused severe pulmonary arterial hypertension, with a Fulton index of 0.73?±?0.07, reductions in both the pulmonary arterial acceleration time and pulmonary arterial acceleration to pulmonary arterial ejection times ratio, and extensive medial hypertrophy and occlusive neointimal lesions. Whereas the normotensive circulation accommodated large increases in forward and retrograde flow, the hypertensive circulation did not. During forward flow, pulmonary artery and double occlusion pressures rose sharply at low perfusion rates, resulting in hydrostatic edema. Pulmonary arterial hypertensive lungs possessed an absolute intolerance to retrograde perfusion, and they rapidly developed edema. Retrograde perfusion was not rescued by maximal vasodilation. Retrograde perfusion was preserved in lungs from animals treated with Sugen 5416 and hypoxia for 1 and 3 wk, in lungs from animals with a milder form of hypoxic hypertension, and in normotensive lungs subjected to high outflow pressures. Thus impaired retrograde perfusion coincides with development of severe pulmonary arterial hypertension, with advanced structural defects in the microcirculation.
| S-EPMC6008136 | biostudies-literature
Project description:Key pointsThe distribution of pulmonary perfusion is affected by gravity, vascular branching structure and active regulatory mechanisms, which may be disrupted by cardiopulmonary disease, but this is not well studied, particularly in rare conditions. We evaluated pulmonary perfusion in patients who had undergone Fontan procedure, patients with pulmonary arterial hypertension (PAH) and two groups of controls using a proton magnetic resonance imaging technique, arterial spin labelling to measure perfusion. Heterogeneity was assessed by the relative dispersion (SD/mean) and gravitational gradients. Gravitational gradients were similar between all groups, but heterogeneity was significantly increased in both patient groups compared to controls and persisted after removing contributions from large blood vessels and gravitational gradients. Patients with Fontan physiology and patients with PAH have increased pulmonary perfusion heterogeneity that is not explainable by differences in mean perfusion, gravitational gradients, or large vessel anatomy. This probably reflects vascular remodelling in PAH and possibly in Fontan physiology.AbstractMany factors affect the distribution of pulmonary perfusion, which may be disrupted by cardiopulmonary disease, but this is not well studied, particularly in rare conditions. An example is following the Fontan procedure, where pulmonary perfusion is passive, and heterogeneity may be increased because of the underlying pathophysiology leading to Fontan palliation, remodelling, or increased gravitational gradients from low flow. Another is pulmonary arterial hypertension (PAH), where gravitational gradients may be reduced secondary to high pressures, but remodelling may increase perfusion heterogeneity. We evaluated regional pulmonary perfusion in Fontan patients (n = 5), healthy young controls (Fontan control, n = 5), patients with PAH (n = 6) and healthy older controls (PAH control) using proton magnetic resonance imaging. Regional perfusion was measured using arterial spin labelling. Heterogeneity was assessed by the relative dispersion (SD/mean) and gravitational gradients. Mean perfusion was similar (Fontan = 2.50 ± 1.02 ml min-1 ml-1 ; Fontan control = 3.09 ± 0.58, PAH = 3.63 ± 1.95; PAH control = 3.98 ± 0.91, P = 0.26), and the slopes of gravitational gradients were not different (Fontan = -0.23 ± 0.09 ml min-1 ml-1 cm-1 ; Fontan control = -0.29 ± 0.23, PAH = -0.27 ± 0.09, PAH control = -0.25 ± 0.18, P = 0.91) between groups. Perfusion relative dispersion was greater in both Fontan and PAH than controls (Fontan = 1.46 ± 0.18; Fontan control = 0.99 ± 0.21, P = 0.005; PAH = 1.22 ± 0.27, PAH control = 0.91 ± 0.12, P = 0.02) but similar between patient groups (P = 0.13). These findings persisted after removing contributions from large blood vessels and gravitational gradients (all P < 0.05). We conclude that patients with Fontan physiology and PAH have increased pulmonary perfusion heterogeneity that is not explained by differences in mean perfusion, gravitational gradients, or large vessel anatomy. This probably reflects the effects of remodelling in PAH and possibly in Fontan physiology.
| S-EPMC8315789 | biostudies-literature
Project description:Microarray analysis of peripheral blood mononuclear (PBMC) cells in pulmonary arterial hypertension. Keywords = mononuclear cells Keywords = gene microarray Keywords = pulmonary arterial hypertension Keywords = Herpesvirus Keywords = biomarker Keywords: other
2003-11-15 | GSE703 | GEO
Project description:Mechanisms underlying pulmonary arterial hypertension (PAH) remain elusive. Pulmonary arterial hypertension and exercise PH share similar physiologic consequences; it is debated whether they share biologic mechanisms and if exercise PH represents an early phase of pulmonary arterial hypertension. We conducted an observational study to test if there is a graded metabolic disturbance along the severity of PH, which may indicate shared or disparate pathophysiology. Individuals referred to an academic medical dyspnea center with unexplained exertional intolerance underwent invasive cardiopulmonary exercise testing. We identified controls with no hemodynamic exercise limitation, individuals with exercise PH (mean pulmonary arterial pressure (mPAP) < 25 mmHg at rest but ≥ 30 mmHg during exercise without pulmonary venous hypertension) and pulmonary arterial hypertension (mPAP > 25 mmHg at rest without pulmonary venous hypertension) (n = 26 in each group). Unbiased metabolomics with chromatography mass spectrometry was performed on pulmonary arterial blood at rest and peak exercise. Random forest analysis and hierarchical clustering were used to quantify metabolite prediction of group membership and rank metabolites which were significantly different between groups. Compared to controls, pulmonary arterial hypertension subjects exhibited perturbations in pathways involving glycolysis, TCA cycle, fatty acid and complex lipid oxidation, collagen deposition and fibrosis, nucleotide metabolism, and others. The metabolic signature of exercise PH was uniquely between that of control and pulmonary arterial hypertension subjects. Accuracy predicting control, exercise PH, and pulmonary arterial hypertension group was 96%, 90%, and 88%, respectively, using paired rest-exercise metabolic changes. Our data suggest the metabolic profile of exercise PH is between that of controls and patients with pulmonary arterial hypertension.
| S-EPMC6822198 | biostudies-literature
Project description:Cardiac magnetic resonance imaging (CMRI) provides accurate information about right ventricular (RV) mass, RV volumes and other markers of RV function. CMRI is proving to be a particularly useful tool in pulmonary arterial hypertension (PAH), as measures of RV function have been shown to be prognostic of long-term outcomes in this disease. Changes in RV function can also provide important information about a patient's disease course and response to treatment. As CMRI is noninvasive it can be used to regularly monitor patients with PAH, which is an important advantage over invasive right heart catheterisation. This review will explore the use of CMRI in the context of existing monitoring tools for PAH and will explore the forthcoming developments that are likely to be important in the future monitoring of patients with PAH.
| S-EPMC9639186 | biostudies-literature
Project description:BackgroundPulmonary arterial hypertension (PAH) is a progressive pulmonary vascular disease with a high mortality rate that can be divided into different groups according to etiology and prognosis. Few studies have investigated differences in the exercise capacity and quality of life (QOL) among the different groups of PAH patients. Therefore, we aimed to (1) compare the hemodynamic exercise responses between patients with idiopathic pulmonary arterial hypertension (IPAH) and PAH associated with other diseases (APAH), and (2) determine the factors associated with exercise capacity in patients with PAH.MethodsSix patients diagnosed with IPAH and eight with APAH [congenital heart disease (CHD)-dominant PAH] were included in this study. The main outcome measures included body composition, exercise capacity, hemodynamic measurements, physical activity levels, fatigue severity, and QOL.ResultsThe CHD-dominant PAH group had a significantly lower predicted peak oxygen consumption (VO2pred %), pressure of end-tidal carbon dioxide at the peak and at anaerobic threshold (PETCO2peak and PETCO2@AT), and significantly elevated ventilatory equivalent (VE/VCO2slope and VE/VCO2@AT) compared with the IPAH group. Multiple regression analysis indicated that PETCO2@AT was significantly associated with either VO2peak (β = 0.805, adjusted R2 = 0.619, p = 0.001) or 6-minute walk distance (β = 0.816, adjusted R2 = 0.638, p < 0.001).ConclusionsPatients with CHD-dominant PAH had poor exercise capacity and exercise responses compared to those with IPAH. Evaluating exercise capacity and the patient response to exercise using cardiopulmonary exercise testing is increasingly important in view of the etiology of PAH.
| S-EPMC7814335 | biostudies-literature
Project description:The objective of this prospective study was to assess short- and long-term efficacy of exercise training (ET) as add-on to medical therapy in patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-APAH).Patients with invasively confirmed CTD-APAH received ET in-hospital for 3 weeks and continued at home for 12 weeks. Efficacy parameters have been evaluated at baseline and after 15 weeks by blinded-observers. Survival rate has been evaluated in a follow-up period of 2.9 ± 1.9 years.Twenty-one consecutive patients were included and assessed at baseline, and after 3 weeks, 14 after 15 weeks. Patients significantly improved the mean distance walked in 6 minutes compared to baseline by 67 ± 52 meters after 3 weeks (p < 0.001) and by 71 ± 35 meters after 15 weeks (p = 0.003), scores of quality of life (p < 0.05), heart rate at rest, peak oxygen consumption, oxygen saturation and maximal workload. Systolic pulmonary artery pressure and diastolic systemic blood pressure improved significantly after 3 weeks of ET. The 1- and 2-year overall-survival rates were 100%, the 3-year survival 73%. In one patient lung transplantation was performed 6 months after ET.ET as add-on to medical therapy is highly effective in patients with CTD-APAH to improve work capacity, quality of life and further prognostic relevant parameters and possibly improves the 1-, 2- and 3-year survival rate. Further randomized controlled studies are needed to confirm these results.ClinicalTrials.gov: NCT00491309.
| S-EPMC3446533 | biostudies-literature
Project description:Borderline resting mean pulmonary arterial pressure (mPAP) is associated with adverse outcomes and affects the exercise pulmonary vascular response. However, the pathophysiological mechanisms underlying exertional intolerance in borderline mPAP remain incompletely characterized. In the current study, we sought to evaluate the prevalence and functional impact of exercise pulmonary hypertension (ePH) across a spectrum of resting mPAP's in consecutive patients with contemporary resting right heart catheterization (RHC) and invasive cardiopulmonary exercise testing. Patients with resting mPAP <25?mmHg and pulmonary arterial wedge pressure ?15?mmHg (n?=?312) were stratified by mPAP?<?13, 13-16, 17-20, and 21-24?mmHg. Those with ePH (n?=?35) were compared with resting precapillary pulmonary hypertension (rPH; n?=?16) and to those with normal hemodynamics (non-PH; n?=?224). ePH prevalence was 6%, 8%, and 27% for resting mPAP 13-16, 17-20, and 21-24?mmHg, respectively. Within each of these resting mPAP epochs, ePH negatively impacted exercise capacity compared with non-PH (peak oxygen uptake 70?±?16% versus 92?±?19% predicted, P?<?0.01; 72?±?13% versus 86?±?17% predicted, P?<?0.05; and 64?±?15% versus 82?±?19% predicted, P?<?0.001, respectively). Overall, ePH and rPH had similar functional limitation (peak oxygen uptake 67?±?15% versus 68?±?17% predicted, P?>?0.05) and similar underlying mechanisms of exercise intolerance compared with non-PH (peak oxygen delivery 1868?±?599?mL/min versus 1756?±?720?mL/min versus 2482?±?875?mL/min, respectively; P?<?0.05), associated with chronotropic incompetence, increased right ventricular afterload and signs of right ventricular/pulmonary vascular uncoupling. In conclusion, ePH is most frequently found in borderline mPAP, reducing exercise capacity in a manner similar to rPH. When borderline mPAP is identified at RHC, evaluation of the pulmonary circulation under the stress of exercise is warranted.
| S-EPMC5841910 | biostudies-literature